[Bug ipa/88900] New: [9 Regression] 502.gcc_r SPEC benchmark miscompiles with LTO and PGO

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88900

            Bug ID: 88900
           Summary: [9 Regression] 502.gcc_r SPEC benchmark miscompiles
                    with LTO and PGO
           Product: gcc
           Version: 9.0
            Status: UNCONFIRMED
          Keywords: needs-bisection, needs-reduction
          Severity: normal
          Priority: P3
         Component: ipa
          Assignee: unassigned at gcc dot gnu.org
          Reporter: marxin at gcc dot gnu.org
                CC: marxin at gcc dot gnu.org
  Target Milestone: ---

Can be seen on a Ryzen machine and Haswell with following flags:

OPTIMIZE    = -Ofast -march=native -g -flto=8
CXXOPTIMIZE  = -fpermissive
FOPTIMIZE    = -std=legacy

PASS1_OPTIMIZE    = -fprofile-generate
PASS2_OPTIMIZE    = -fprofile-use -fprofile-correction

I'm bisecting problematic revision.